Cracked block - fixable?

[torch]

Nevermind JB Weld or similar on the outside. Get a can of CRC Block Seal. Unlike most cooling system sealants, this stuff actually works long term. The gotcha is the system has to be completely flushed of anti-freeze before adding the product. Then completely flushed after treatment before replacing with anti-freeze. But if you follow the directions religiously it works well.

 

[airbiscuit]

There was another thread around here concerning an epoxy repair on a block...

https://www.orangetractortalks.com/forums/threads/fixing-hole-in-side-of-block.69038/page-18

There's a bunch, but start at #360

 

[whitetiger]

There was another thread around here concerning an epoxy repair on a block...

 

[airbiscuit]

66 pages

 

[number two]

Anybody remember waterglass from the drugstore for fixing large cracks?
Good Luck!

 

[Lil Foot]

My JB weld story, posted previously:

"Years ago I was at a drag strip watching a gorgeous blonde woman run a long gas dragster in the 8-9 sec range. Went to her pit to talk to her and she showed us the car. It had a built 327, with no radiator, and had to be cooled between passes. I noticed a repair on both sides of the block, about 8-10" long, below the deck & above the block drain. Her husband said they found the car in a storage facility in Colorado, where it had been stored with no anti freeze, splitting the block. They bought the car for $400, ground out the cracks to a "vee", cleaned everything, and troweled in JB Weld. The car had been running 20 years on that repair. That was what initially sold me on JB Weld. Good stuff."

That repair was on a wide flat area, with little to no stresses, and probably less heat and less rapid temperature swings than the original posters problem.

YMMV.

 

[D2Cat]

If I were doing the JB repair I would take a 16P nail and bend the end 90 deg about half inch from the point. Use that to scrape the crack just to clean it out a bit. Then when applying the JB have a piece of duct tape ready to put over the whole thing. This keeps the JB from flowing out/down the cracked area.

I did a similar repair on a JD 350 crawler block. Had about a 4" horizontal crack below the freeze plug. Cleaned it, applied JB and covered with tap. Never messed with it for about a week. As far as I know it was running 10 years later.

 

[Runs With Scissors]

To be successful using JB Weld, I think you need to start by getting a can full of gasoline and pressurizing it ……………………..





EDIT: I’m also in the “Don’t waste your time” camp…………..

 

[hedgerow]

Anybody remember waterglass from the drugstore for fixing large cracks?
Good Luck!

I used it on a old JD model G forty plus years ago for a cracked head issue. It was still holding twenty years later when I sold the tractor. I told the guy what I had done twenty years before. He didn't care as the tractor was going to be used for tractor pulling and was getting a different engine.

 

[Vanguard08]

I don't really know what to expect so I won't be getting my hopes up but like someone else mentioned, it's a cheap test so I figure no harm no foul.

I took some more pictures so you can better place the crack. I whiped it down, used vinegar to clean off any residue and rust, and then used a steel wheel Dremal brush to get a better clean all over it, then I used a torch to burn off anything around it. I did this a few times trying to get it as clean as I could.

Here's a few pictures:

Here's a better picture of the crack after I whiped it down with some vinegar:

It does come from underneath though so it's a bit worse than it looks. Not a lot... but enough that it's gonna count.

Here's a zoomed out view I took after I removed the fuel tank:

Here's a picture after a bit of cleaning, you can start to see it more clearly:

And... here's a picture of my probably laughable attempt to patch this thing up. Not the prettiest but I did try to get a nice even glob spread all around the area:

I'll let that sit for a day or two and then we'll see what's what.

 

[North Idaho Wolfman]

That's just a head crack.
aand it's more than likely only external.
If you pull the head you could get it fixed properly and never have an issue again.

 

[nave.lb]

Maybe i'm too late here....have you considered high content silver braze? It may not be a feasible Option depending on the crack and how far you want to go. But it is a really good repair for cast iron. Just food for thought.

 

[North Idaho Wolfman]

Maybe i'm too late here....have you considered high content silver braze? It may not be a feasible Option depending on the crack and how far you want to go. But it is a really good repair for cast iron. Just food for thought.

He would need to pull the head to do that repair, but that crack might be repairable, would need to see the bottom of the head.

 

[airbiscuit]

I'm thinking his JB weld fix is going to work. Waiting for an update

 

[North Idaho Wolfman]

I'm thinking his JB weld fix is going to work. Waiting for an update

It might work until it doesn't.

 

[Vanguard08]

Welp...

Good and bad.

So far the JB is holding... but it's hardly a good enough test. I only let it run for a short while so it'll take putting it to work for a couple days before I think the patch will hold for any amount of time. I took a picture of the patched crack while running but it's kinda pointless to post it. It's just the same picture, it's dry and not leaking at the crack area.

However...

While that crack has been dealt with (even if just for the moment) I'm not out of the woods yet. Found at least one more maybe-serious spot.

Here's a backed away picture to place the spot:

Here's a couple pictures of the same spot zoomed in on it:

Looks like this isn't held in flush and it should be?

I know I'm supposed to keep everything on this site but I don't think I can put a video here can I? I'll just call this bonus content.
I just uploaded it to Streamable.com: B7100 Leak
It just shows the motor running, zoomed in on the JB, dry as a bone... but then shows the new leak.

I just came in from messing with it so I haven't started studying up on what I'm looking at yet but this is the new challenge. Unless this is a *quit-now* type situation, this leak won't drain me quickly so tomorrow or Saturday I'll do some work with it to confirm the JB is gonna last more than a few hours. TBD on the rest.

 

[L35]

It looks like the 2nd leak is from a pushed out freeze plug. I wonder if like you said your engine froze solid and that’s what could have cracked it?

Anyway congratulations on the so far successful 1st leak repair!

 

[airbiscuit]

Maybe do this first

 

[torch]

The video of your leak is very instructive.
This may be in your future

I'm not familiar with the Fiberlock product, but I have used the Block Seal product quite successfully on a couple of engines. It was recommended to me by a mechanic who swore by the stuff.

 

[North Idaho Wolfman]

You should NOT use any sealer in this engine.
It's a thermosiphon system aka NO water pump for circulation.
Any type of sealer will just sit at the lowest point and plug that up.